{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{6}{c}}
\hline\hline
            &         CDD   &               &               &         CDI   &               &               \\
            &\multicolumn{1}{c}{6 M.}&\multicolumn{1}{c}{18 M.}&\multicolumn{1}{c}{Pooled}&\multicolumn{1}{c}{6 M.}&\multicolumn{1}{c}{18 M.}&\multicolumn{1}{c}{Pooled}\\
\hline
assignment  &        0.09***&        0.06*  &        0.07***&       -0.00   &        0.02   &        0.01   \\
            &      (0.03)   &      (0.03)   &      (0.03)   &      (0.04)   &      (0.04)   &      (0.03)   \\
\hline
\(R^{2}\)   &       0.157   &       0.146   &       0.136   &       0.410   &       0.362   &       0.384   \\
Mean        &        0.13   &        0.13   &        0.13   &        0.47   &        0.39   &        0.43   \\
\(N\)       &         808   &         828   &        1636   &         897   &         828   &        1725   \\
\hline\hline
\end{tabular}
}
